On-line mercury speciation in exhaust gas by using solid-phase chemical reduction

Speciation of mercury species in exhaust gas from combustion sources is important for both the design of equipment for mercury pollution control and incinerator operation control. A simple, portable atomic absorption spectrometer is described that can monitor, in real time, the mercury species present in stack gas. A SnCl2-loaded reduction column was used to convert molecular mercury to mercury atoms, which were then detected by atomic absorption spectrometry. The adoption of solid-phase reduction of the molecular species simplified the instrument design and made analysis easier. Results presented in this paper demonstrate the potential of the proposed method for field application.